From what I can tell of the development timeline posted in the roadmap, there is zero content planned for basically any of the inland states except for maybe some stuff around the Great Lakes region. Especially west of the Mississippi, where Alberta is the only nation not touching the ocean to have a custom focus tree.

I know a lot of these areas are nicknamed flyover states, but its not like there's nobody there. Hell, with the amount of nations there, it'd basically demand a standalone section added to the end of the current roadmap based on what looks to be the 4-5 focus trees/update.